1. Field of the Invention
The present invention relates to a data storage device for recording data on a memory medium, such as a magneto-optical disk, and in particular to a data storage device which ensures the secrecy and the security of recorded data.
2. Related Arts
Generally, a data writable memory medium, such as a magneto-optical disk (MO), can be inserted into or removed from a data storage device (hereinafter simply referred to as a storage device) which reads and writes predetermined data from and to. When a memory medium is loaded into the storage device, operational control for the storage device is provided by commands issued by a superior apparatus, such as a personal computer connected to the storage device by a SCSI cable.
Conventionally, by taking compatibility into account, reading data from and writing data to a memory medium can also be performed by a storage device other than the device which was originally employed for writing data.
FIG. 28 is a flowchart for a data reading/writing process performed by a conventional storage device. After a memory medium is set to (for example, inserted into) the storage device at step S1, at step S2 the medium is loaded. That is, the memory medium is positioned at a predetermined location within the storage device and is rotated at a controlled revolution rate. At step S3, predetermined data relevant to the memory medium, such as its configuration and its memory capacity, are read, and at step S4 the reading and writing of data is enabled by the employment of an operation or a process procedure. based on data corresponding to that for the memory medium.
Therefore, a problem has arisen in that once a memory medium has been acquired, secret data recorded on the memory medium, such as the contents of a client database or design data, can easily be stolen or altered.
It is, therefore, one objective of the present invention to provide a data storage device that ensures the secrecy and the security of data recorded on a memory medium.
To achieve the above objective, according to the present invention, it is provided a data storage device which reads data from and/or writes data to a memory medium, comprises:
a storage unit for storing a first identifier;
an identifier acquisition unit for acquiring a second identifier recorded on a memory medium which is set to said data storage device; and
a controller for comparing said first identifier with said second identifier, and controlling to access to said memory medium for data reading and/or writing according to a relationship between said first identifier and said second identifier.
For example, when the first identifier recorded in the storage unit does not match the second identifier recorded on the memory medium, the controller inhibits access to the memory medium for the reading and writing of data. But when the first and the second identifiers match, the controller permits access to the memory medium for the reading and writing of data.
As described above, since the storage device having an identifier which differs from the identifier recorded on the memory medium inhibits access to the memory medium for the reading and writing of data, the secrecy of data recorded on the memory medium is ensured.
Read address information to be used to control reading of data and/or write address information to be used to control writing of data are stored in a predetermined area on the memory medium. When the first identifier matches the second identifier, the controller may permit or inhibit the reading and/or writing of data according to the read address information and/or the write address information respectively.
In addition, to achieve the above objective, according to the present invention, it is provided a data storage device which reads data from and/or writes data to a memory medium by designating first address information, comprises:
a storage unit for storing a first identifier;
an identifier acquisition unit for acquiring a second identifier recorded in a memory medium which is set to said data storage device;
an address information acquisition unit for acquiring second address information recorded in said memory medium; and
a controller for comparing said first identifier with said second identifier and said first address information with said second address information, and controlling to access to said memory medium for data reading and/or writing according to a relationship between said first identifier and said second identifier and a relationship between said first address information and said second address information.
The first identifier and the second identifier are identifiers inherent to a data storage device or identifiers inherent to a memory medium. For example, the identifier inherent to a data storage device or memory medium is a serial number of a data storage device or a memory medium.
Thus, Security can be established for each of a plurality of data items recorded on a memory medium.
Read address information to be used to control reading of data and/or write address information to be used to control writing of data are stored in a predetermined area on the memory medium. When the first identifier matches the second identifier and the second address information is included in the first address information, the controller may permit or inhibit the reading and/or writing of data according to the read address information and/or the write address information respectively.
In this structured data storage device, the controller records the second identifier, the read address information, the write address information, or the second address information in the predetermined area based on a predetermined setup command which is transmitted by a control device of a data storage device connected to the data storage device.
A predetermined setup command is, for example, a SCSI interface format command or a vender unique command.
Further, it is preferable that the controller can initialize a predetermined area based on a predetermined release command, which is transmitted from the control device of a data storage device connected to the data storage device.
Other features and advantages of the present invention will become readily apparent from the following description when taken in conjunction with the accompanying drawings.